Class TelemetryPercentile

Namespace

Typhon.Engine

Assembly

Typhon.Engine.dll

The engine's one definition of a percentile over telemetry samples: nearest-rank, no interpolation.

public static class TelemetryPercentile

Inheritance

object

TelemetryPercentile

Inherited Members

object.GetType()

object.MemberwiseClone()

object.ToString()

object.Equals(object)

object.Equals(object, object)

object.ReferenceEquals(object, object)

object.GetHashCode()

Remarks

It lives in one place because two paths report the same numbers to different audiences — the STATS wire block to game clients, and ReadStats(int) to an HTTP endpoint, a CLI verb or a log line. Two implementations of "p99" that disagree by a rank produce two plausible-looking figures for one tick, and whichever a reader happens to see becomes the one they trust. A shared function makes them equal by construction rather than by review.

Nearest-rank, deliberately. An interpolated percentile invents a value between two measured ticks, which for a latency figure means reporting a duration no tick had. At the window sizes here — one second, so 50 samples at 50 Hz — interpolation also moves the answer more than the sampling noise it is meant to smooth.

Methods

NearestRank(double[], int, double)

The nearest-rank percentile of the first count samples.

public static double NearestRank(double[] samples, int count, double q)

Parameters

samples double[]

The samples. Reordered in place — the caller must not rely on their order afterwards.

count int

How many leading entries of samples are live samples.

q double

The percentile, in [0, 1]. 0.5 is the median.

Returns

double

The sample at the nearest rank, or 0 when there are no samples.

Remarks

Sorting in place is what keeps this allocation-free on the STATS path, which reuses one buffer sized at construction and must not allocate after it. Zero for an empty window is a reading, not a sentinel: a runtime that has not ticked has no duration, and a caller that needs to tell the two apart reads the sample count it passed in.